The acoustic guitar is a popular musical instrument for both amateurs and professional musicians. The acoustic guitar has a hollow body connected to a neck. The body has a backboard and a soundboard, with a soundhole, connected to the backboard by a shaped sidewall. The neck and body are connected together at a neck to body joint.
The acoustic guitar has a series of strings strung at substantial tension from a bridge on the soundboard, across the soundhole, and along the neck. The string tension creates forces which act on the soundboard and the neck to body joint. Over time, these forces can cause bending, cracking or other damage to the soundboard, and they are the principal cause of structural failure and altered intonation of the acoustic guitar.
Prior art designs have attempted to improve upon the strength and durability of acoustic guitars without adversely affecting its playing qualities. For instance, U.S. Pat. Nos. 3,656,395; 3,685,385; and 4,079,654 disclose various bracing patterns on the underside of the soundboard. U.S. Pat. Nos. 3,974,730 and 4,027,570 disclose neck to body joint configurations for strengthening the joint area of the guitar.
In a high quality acoustic guitar, the bracing structure of the soundboard must be strong enough to withstand the forces created by the tensioned strings. However, the bracing structure must also allow the soundboard to vibrate sufficiently freely so that it does not interfere with the acoustical function of the soundboard. These requirements are at cross-purposes, and heretofore they have been very difficult to achieve by means of known techniques.
The neck to body joint of a quality acoustic guitar must secure the neck at a specific angle, or pitch, relative to the body. Variations from the design angle can adversely affect the playability of the guitar. Moreover, the neck to body joint must be stable enough to withstand the forces created by the tensioned strings. Heretofore, these goals have been difficult to achieve on a consistent basis using known guitar-making techniques.